Inflatable structure



ly 25, 6 LE ROY c. KNETZER 3,332,176

INFLATABLE S TRUCTURE S Filed March 5, 1962 2 Sheets-Sheet 1 INVENTOR. LEROY c. KNETZER BYWEW A T TOR/VE Y 1967 LE ROY c. KNETZER I NFLATABLE S TRUC TURES 2 Sheets-Sheet 2 Filed March 5, 1962 FIG.

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INVENTOR. LEROY C. KNETZER 8Y2! {fa 4 ATTORNEY United States Patent 3,332,176 INFLATABLE STRUCTURE Le Roy C. Knetzer, Rockford Township, Sedgwick Coun. ty, Kans., assignor of one-half to Robert E. Breidenthal, Wichita, Kans.

Filed Mar. 5, 1962, Ser. No. 177,657 16 Claims. (Cl. 52--2) This invention relates to new and useful improvements in inflatable structures, and more particularly pertains to the inflating and deflating and/or the support of such structure.

Many multi-celled inflatable structures have heretofore been proposed, some of which have included conduit and valve means between adjacent cells such that they can all be filled through an inlet to one cell and such that rupture of one cell will not result in total deflation of the other cells; however, structures heretofore proposed are subject to one or more of a number of shortcomings. Among such shortcomings may be mentioned the fact that all the cells cannot be deflated through the inlet used for filling, the valve means are such that the cells are filled so that there is a progressive pressure drop from cell to cell in the direction of movement of the inflating fluid, the cells are simultaneously deflated, the inflated structure lacks sufiicient strength, etc.

It is the primary purpose of this invention to overcome the aforementioned shortcomings.

An important object of the invention is to provide a multi-celled inflatable structure such that the cells can be sequentially inflated to a single predetermined pressure, which pressure can be a certain amount in excess of ambient or atmospheric pressure.

Another important object of the invention is to provide a multi-celled inflatable structure such that the cells can be sequentially deflated, preferably to a single predetermined pressure, which pressure can differ by a certain amount from ambient or atmospheric pressure.

A further object of the invention is to provide a multicelled inflatable structure in accordance with the preceding objects in which the cells can be deflated in the same or inverse order with respect to the order in which they are inflated.

Another object of the invention is to provide a pressure-differential response valve that opens only when the pressure differential has a value greater and less than a predetermined range.

Yet another object of the invention is to provide a pressure-diflerential responsive valve of the diaphragm type such that the valve controlled passageway extends through the diaphragm.

An important object of the invention is to provide an inflatable structure that is self-erecting during inflation.

Yet another important object of the invention is to provide an inflatable structure that is self-retracting on deflation.

A final object to be specifically given is to provide a sturdy inflatable structure having a double-walled generally hemispherical configuration, the interior of which structure is subdivided into a plurality of lune-shaped cells by partitions having fluid passageways therethrough that can optionally be provided with valve means.

Though other important objects and purposes of the invention will subsequently become apparent, the last to be specifically enumerated is to provide an articulated frame in combination with an inflatable structure so as to lend stabilizing support and rigidity to the latter on inflation, and so as to guide and lend support to the cells during their inflation and/ or deflation.

The instant invention involves an improvement in an article of manufacture comprising first and second inflatable cells separated by a partition, means defining a passageway affording fluid communication between the cells, valve means normally closing the passageway, valve control means responsive to a fluid pressure differential in excess of a predetermined value for opening said valve means, and said last means being in operative fluid pressure communication with the interior of the first cell and with a source of substantially constant fluid pressure.

Another aspect of the invention involves an improvement in an article of manufacture comprising first and second inflatable cells separated by a partition, means defining a passageway affording fluid communication between the cells, valve means for the passageway, valve control means responsive to a fluid pressure difierential for maintaining the valve means open when a pressure differential exceeds and is below a predetermined range of values, said valve control means also maintaining the valve means closed when the pressure differential lies within said range of values, said valve control means being in operative fluid communication with the interior of the first cell and with a source of substantially constant fluid pressure.

The invention also has to do with a valve and control means for the valve comprising a bonnet having first and second sides, the central portion of the first side of the bonnet being constituted of a tubular extension having a closed outer end directed away from the second side of the bonnet, an open-ended tubular valving element slideable in the tubular extension, a diaphragm mounted in the bonnet between the first and second sides of the bonnet and secured to the inner end of the valving element, said diaphragm having an opening affording communication therethrough with the interior of the valving element, said tubular extension having a lateral opening therethrough, one of said sides of the bonnet having an opening therethrough, and means for affording fluid pressure communication between the side of the diaphragm adjacent the other side of the bonnet and a source of fluid pressure.

The invention has to do with another form of valve and control means therefor comprising a bonnet having first and second sides, the central portion of the first side of the bonnet being constituted of an open-ended tubular extension directed away from the second side of the bonnet, lateral passageway means in the tubular extension, a valving element slideable in the tubular extension for opening and closing the passageway means, a diaphragm mounted in the bonnet between the first and second sides of the bonnet, the central portion of the diaphragm being operatively connected to the valving element, and means for operatively affording fluid pressure communication between the opposite sides of the diaphragm and two sources of fluid pressure.

A broad aspect of the present invention has to do with an inflatable structure of the type including a pair of cells separated by a partition, and involves the improvement comprising means for affording fluid communication between the cells, and means for entirely closing said last means solely upon the pressures in both of the cells being less than a predetermined value, said closing means including valving means provided with a pressure-differential responsive valve control means.

Another important aspect of the invention has to do with an inflatable structure of the type including a plurality of serially connected cells, and involves the improvement comprising, in relation to each cell and the serially next cell respectively termed the preceding cell and the succeeding cell, means establishing fluid communication between the preceding and the succeeding cells, and means for closing fluid communication solely upon the pressure Within the preceding cell being below a predetermined amount in excess of pressure ambient to the cells, said means including a pressure-differential responsive control device in operative fluid pressure communication with the interior of the preceding cell and space ambient to the cells.

Yet another important aspect of the invention has to do with an inflatable structure of the type including a plurality of serially connected cells, and involves the improvement comprising, in relation to each cell and the serially next cell respectively termed the preceding cell and the succeeding cell, means establishing fluid communication between the preceding cell and the succeeding cell, means for closing said fluid communication solely upon the pressure differential between the interior of the preceding cell and space ambient to the cells lying within a predetermined range, said closing means including a pressure-differential responsive control device in operative fluid pressure communication with the interior of the preceding cell and space ambient to the cells.

The invention also encompasses an inflatable structure comprised of a plurality of serially connected, inflatable cells, each of said cells being generally lune-shaped so that on inflation of the cells the structure has a configuration of at least a portion of a hemispherical, double-Walled shell, and means for sequentially inflating the cells in serial order to a predetermined pressure.

Still another important aspect of the invention has to do with the combination of an inflatable structure and a support frame therefor, wherein said frame is comprised of a plurality of articulated frame elements each connected to the inflatable structure, said frame being articulated to move between collapsed and erected conditions generally conformable to said structure when the latter is deflated and inflated, respectively.

A basic aspect of the invention involves a multi-celled inflatable structure of such character that the same is largely or entirely self-erecting on sequential inflation of the cells so as to move progressively from a collapsed or storage condition to fully erected position, while being largely or entirely self-supporting during the process.

Another aspect of the invention is related to that set forth in the preceding paragraph and involves the reverse procedure and functions on deflation of the structure.

One viewpoint of the invention comprises a doublewalled, inflatable structure of generally hemispherical configuration, the interior of which is for the most part subdivided into generally lune-shaped cells arranged so that the cusps of cells converge toward diametrically opposed portions of the structure, such cells being separated by partitions having passageways therethrough that are optionally, though preferably, provided with valve means for controlling fluid communication through the passage ways. In this embodiment of the invention, it is preferred that the spacing of the double Walls be generally uniform throughout the structure, though optionally such spacing can be tapered and reduced toward the two regions of convergence of the cusps of the cells.

The invention will be best understood in the light of the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a side elevational view; with the left half thereof being in central vertical section and with certain hidden parts being shown in clashed outline; of an inflatable structure according to the invention, the same being shown in erected condition and secured on the surface of the ground;

FIGURE 2 is a top plan view of the structure of FIG- URE 1, with a portion of the cell structure being removed to expose details of the support frame;

FIGURE 3 is a broken schematic illustration of the cell structure of FIGURES 1 and 2 to show the cell layout, valve system, and the pumps;

FIGURE 4 is an enlarged cross-sectional detail view of the valve and control means therefor shown in FIG- URES 1, 2 and 3;

FIGURE 5 is an enlarged fragmentary detail view in 4 elevation of the type partition separating the cells of the structure shown in FIGURES 1 and 2, the hidden supporting slats being indicated in dashed outline;

FIGURE 6 is an enlarged cross-sectional detail view taken upon the plane of the section line 6-6 in FIG- URE 5;

FIGURE 7 is an enlarged fragmentary sectional view of the external or side wall of a cell;

FIGURE 8 is a schematic illustration for the purpose of showing the action occurring upon succeesive inflation of a sequence of cells according to the invention;

FIGURE 9 is an enlarged cross-sectional view of a modified form of valve and control means therefor; and,

FIGURE 10 is a schematic illustration of a sequence of connected cells employing the valve and control means therefor shown in FIGURE 9.

Referring to the drawings, wherein like numerals designate similar parts throughout the various views, and with attention being first directed to FIGURES 1 and 2, the reference numeral 10 designates generally an inflatable structure and the numeral 12 designates generally a support frame for the structure 10.

The structure 10 is comprised of a series of lune-shaped cells 14, 16, 18, 20, 22, 24, 26, 28, 30 and 32 that are fluid tight and separated by shared or common partitions 34, 36, 38, 40, 42, 44, 46, 48 and 50. The cell 14 is closed on its side opposite the partition 34 by an end wall 51. A pair of cells 52 and 54, separated by a common partition 56, are connected to cell 32 with the cells 52 and 32 being separated by a common partition 58. The cell 54 is closed on its side opposite the partition 56 by an end wall 59. As partly shown in FIGURE 2, a further pair of cells 60 and 62, separated by a common partition 64, are connected to the cell 32, with the cells 60 and 32 being separated by a common partition 66. The cell 62 is also closed by an end wall (not shown) similar to the end wall 59.

When the cells 14-32, 52, 54, 60 and 62 are inflated as shown in FIGURES 1 and 2, the structure 10 has a configuration generally similar to a hemisphere affording shelter to a generally circular ground area. It will be noted that the adjacent ends of the pairs of cells 52 and 54, and 60 and 64 are spaced to afford a doorway or entrance 68 to the space sheltered by the structure 10. The adjacent ends of the partitions 58 and 66 are connected by an external wall 70 to constitute what may be deemed a lintel for the doorway 68.

The structure 10, when the cells forming the same are inflated, is secured to the ground surface 72 by means of spaced securing tabs 74 and 76 fixed to the outer walls of the cells 14 and 54, respectively. The tabs 74 and 76 are attached by short flexible lines or cords 78 to anchoring means 80 embedded in the ground 72. The cell 62 is secured to the ground (by means not shown) in a manner similar to that provided for cell 54.

The frame 12 is comprised of a plurality of arcuate or roughly semicircular elements 82, 84, 86 and 88, braced, if desired, as shown, for structural strength. The frame elements 82, 84, 86 and 88 are preferably of lightweight metallic construction, and can conveniently be tubular aluminum or galvanized steel, though wood or suitable plastics can be used. The support frame 12 is articulated by means of the opposite ends of the elements 82, 84, 86 and 88 being hinged together for independent pivotal motion of each of such elements. Although only one of the two hinges means is visible in the drawings at 90, such two hinge means are disposed adjacent and on a line passing through the two diametrically opposed positions 92 and 94 where the cusps or narrow ends of the cells of the structure 10 converge. Each of the hinge means can include a base plate such as that indicated at 96 for the hinge means 90. The base plate 96 rests upon the ground surface 72 and underlies the cusp portions of the cells of the structure 10.

The articulated frame 12 is detachably secured to the cell structure 10. As clearly shown in FIGURE 1, the

frame elements 82 and 84 are releasably secured to the cell structure adjacent the partitions 50 and 46, respectively, by means of straps and snap fasteners 98 and 100. It will be understood that each of the frame elements 82, 84, 86 and 88 is similarly attached to the cell structure 10 at spaced positions along their lengths. The reason for the detachable connection between the cell structure 10 and the support frame 12 is that the use of the latter is optional and can, if desired, be dispensed with. Although the support frame 12 is shown as being disposed within or below the cell structure 10, the support frame can, if desired, be disposed to be outside or above the cell structure. Also optionally, the support frame may be anchored when in the position shown in FIGURES l and 2. Such anchoring can comprise a flexible cable 102 secured at spaced positions along its length to the frame elements as indicated at 104 and 106, and having its opposite ends secured to ground anchors such as the one indicated at 108.

Means is provided for sequentially inflating the cells 1432, cell 52 (and cell 64) and cell 54 (and cell 62) in either forward or reverse order assuming the cells to be initially deflated. Means is also provided, assuming the cells to be initially inflated, for sequentially deflating the cells in the order above given, or in reverse order. Such inflating and deflating means will be understood upon reference to FIGURES 3 and 4, FIGURE 3 being a schematic illustration of the cell structure 10 incorporating the valve structure shown in FIGURE 4.

The valve shown in FIGURE 4, designated generally at 109, comprises a bonnet formed of dished plates 110 and 112 having their peripheries suitably secured with the outer periphery of a flexible diaphragm 114 engaged therebetween. The central portion of the bonnet plate 112 is formed as a tubular extension 1 16 having a closed outer end 118. A tubular valving element 120 is slidingly fitted in the tubular extension 116, and is yieldingly biased from the closed end 118 of the latter by means of a coiled compression spring 122 seated between such end 118 and internal rib 124 in the valving element 120. The valving element 120 is open-ended and the end thereof adjacent the diaphragm 114 is sealingly secured to the diaphragm 114 about the periphery of a central opening 124 in the latter by means of a flange 126 on the valving element 120 and a retaining ring 128 suitably secured thereto between which the diaphragm is engaged. A coiled compression spring 130 has one end received within the retaining ring 128 and is biased between the valving element 120 and the bonnet plate 110 in opposition to the spring 122. The tubular extension 116 is provided with a plurality of circumferentially spaced openings 132 intermediate its ends, and the valving element 120 is similarly provided with openings 134. The arrangement is such that in the position shown of the valving element 120, the latter closes the openings 132, but upon sufficient movement of the valving element 120 to the left, the openings 132 are cleared by the valving element 120 and communication is established between the openings 132 and the space intermediate the bonnet plate 111 and the diaphragm 114 through the valving element 120 and the diaphragm 114. On the other hand, sufficient movement of the valving element 120 to the right to bring the opening 132 and 134 into registry will also establish similar communication.

The valve 109 is shown as applied between a pair of cells 136 and 138 separated by a common partition 140, such cells 136 and 138 having outer or side walls 142 and 143, respectively, to which the partition 140 is sealingly secured. It should be understood that the cells 136 and 138 are independent and fluid tight. The valve 109 is fitted to close an opening 144 in the partition 140. In the preferred construction, the valve 109 includes a cupshaped housing 146 centrally secured to the end 118 of the tubular extension 116 by means of a screw 148, the arrangement being such that tightening of the screw 148 clamps and sealingly secures the periphery of the partition 140 about the opening 144 to the periphery of the bonnet plate 112, as shown. The housing 146 is provided with a set of apertures 150, and it is through one of the apertures 150 that a flexible conduit 152 extends to connect between an opening 154 in the sidewall 143 and a nipple 156 on the bonnet plate 112 in an arrangement affording communication between the space ambient to or outside the cells 136 and 138 and the interior of the bonnet between the diaphragm 114 and the bonnet plate 112. The bonnet plate is provided with a set of apertures 158 which can be as large in size and number as necessary.

The operation of the valve 109 will be readily understood. It will be immediately appreciated that when the openings 132 are closed that the diaphragm 114 has the left side thereof subjected to the pressure prevailing Within the cell 136, and has the right side thereof subjected to the pressure ambient to the cells 136 and 138. It will be assumed for purposes of explanation that the strengths of the springs 122 and are such that the valving element 120 will occupy the position shown thereof when the pressures of the opposite sides of the diaphragm are equal, and it will be further assumed that the ambient pressure communicated through the opening 154 is atmospheric pressure (which may be considered a relatively constant reference pressure). It will be immediately apparent that the opening and closing of the openings 132 is a function of the pressure differential existing between the pressure prevailing within the cell 136 and atmospheric pressure, with the openings 132 being opened when the pressure within the cell 136 exceeds atmospheric pressure by at least a predetermined amount and when the pressure within the cell 136 falls below atmospheric pressure by a predetermined amount, and that the openings 132 are closed at all intermediate pressures within the cell 136 relative to atmospheric pressure. Accordingly, by virtue of the apertures and 158, fluid communication between the cells 136 and 138 can only occur when the pressure in the cell 136 exceeds or falls below atmospheric pressure by predetermined amounts. Thus, for example, on inflation of the'cell 136 to exceed five pounds per square inch gauge (the valve 109 being adjusted to open the openings 132 upon a pressure differential of five pounds per square inch), the valve 109 will open at five pounds per square inch gauge (p.s.i.g.) and the cell 138 will commence to inflate.

Conversely, for example, and assuming the cells 136 and 138 to each being initially at five p.s.i.g. pressure, the valve 109 can be so adjusted that on applying a vacuum pump to exhaust the cell 136 the openings 132 will close and remain closed until the pressure within the cell 136 has dropped to minus one p.s.i.g. pressure after 'which the openings 132 will be opened and the cell 138 can commence to be exhausted.

Although the sliding fit of the valving element 120 in the tubular extension 116 is such that little, if any, leakage will occur between the surfaces of such elements, additional valving means is provided to safeguard against such leakage on movement of the valving element 120 to the right to open the openings 132. Such valving means comprises a resilient annular valve seat of rubber or similar sealing material fixed to one side of the flange 126 for sealing engagement with the bonnet plate 112 adjacent the tubular extension 116. It will be evident that engagement of the valve seat 170 with the bonnet plate 112 will prevent any leakage of the type aforementioned from taking place.

It will be plain that the two limiting pressures aboveand below atmospheric pressure at which the openings 132 are opened by the valving element 120 can be predetermined conveniently by appropriate selection of diaphragm 114 size, strength of the springs 122 and 130 (which need not be identical, and can be such that the range of pressure differentials in which the openings 132 7 are closed does not include zero pressure differential), the location of openings 132 and 134, and the length of the valving element 120 to its end remote from the diaphragm, as will be apparent to those skilled in the art.

Referring now to FIGURE 3, which is a broken schematic representation of the cell structure shown in FIG- URES 1 and 2, it will be noted that flexible conduit means 172 affords fluid communication between the cells 52 and 60, and that flexible conduit means 174 affords fluid communication between the cells 54 and 62. The conduit means 172 and 174 can be arranged as desired to accomplish their function, it being preferred that they be positioned so as not to obstruct the doorway 68. The conduit means 172 and 174 are shown as extending above the doorway 68 and being in part disposed within the cell 32. The conduit means 172 and 174 can extend in sealed relation through the pairs of partitions 58 and 66, and 56 and 64, respectively, to afford communication between the pairs of cells to which they are connected.

A pair of oppositely arranged valves 176 and 178 corresponding to valve 109 is provided in suitable openings in the partition 34. A corresponding pair of oppositely arranged valves 180 and 182 is similarly provided for the partition 36. Although not shown, it is to be understood that partitions 38-50 are similarly provided with oppositely arranged pairs of valves.

The partitions 58 and 66 are provided with oppositely arranged valves 184 and 186, with the partitions 56 and 64 also being provided with oppositely arranged valves 188 and 190. All the valves 184-190 are similar to the valve 109.

Reversible pumps 192 and 194 are respectively connected by suitable and flexible conduit means to the interiors of the cells 14 and 54. The pumps 192 and 194 are of any suitable type for alternatively pumping 1ambient air into their respective cells under superatmospheric pressure, or pumping air out of their respective cells to exhaust them to a subatmospheric pressure. In the event that the pumps 192 and 194 are not selected to be of the positive action type such that fluid flow can not occur through them when not in operation, it is understood that shut off valves are used in conjunction with the pumps 192 and 194 for preventing fluid flow through such pumps. The pumps 192 and 194 can be either manually operable types, or provided with prime movers (not shown). Insofar as the function of the pumps 192 and 194 is to pump air into their respective cells is concerned, they can be replaced by pressurized gas sources, not shown, such as a carbon dioxide cylinder or cartridge, as will be understood by those skilled in the art. The pumps 192 and 194 can, if desired, be of the type including a pressure-regulation feature whereby the pressure to which the cell connected thereto can be limited to a safe value. This latter provision can obviate any need for providing pressure gauges and close supervision by the operator, though of course, any or all the cells can be provided with conventional pressure-venting means, not shown.

Neglecting for the moment the action occurring on the expansion and collapse of the cells of the cell structure 10, and assuming, by way of: example, only that all of the valves 176-190 are adjusted to be closed during pressure differentials between plus five p.s.i.g. to minus one p.s.i.g., the operation of the valves 176-190 will be easily understood. Assuming initially that the cells of the cell structure 10 is atmospheric and that the pump 194 is inactive (or that valve means associated with the pump 194 prevents the flow of air therethrough), operating the pump 192 to force air into the cell 14 will increase the pressure in the cell 14 until the air pressure in cell 14 reaches five p.s.i.g. at which time the valve 176 opens, it being noted that prior to valve 176 opening all the valves 176-190 are closed. Opening of the valve 176 permits air to enter cell 16 as long as the pressure in cell 14 remains in excess of five p.s.i.g. Air continues to 8 enter cell 16 until such time as the pressure therein attains five p.s.i.g. whereupon valve 180 opens to admit air to cell 18.

The sequential pressurization of the cells 14-32 continues until the pressure in cell 32 attains five p.s.i.g. at which time the valve 186 opens to admit air to cell and also to cell 52 via the conduit means 172. After the pressure in cell 60 attains five p.s.i.g., the valve 190 opens to admit air to the cell 62 and also to the cell 54 via the conduit means 174. Upon pressure within the cell 62 attaining a pressure of five p.s.i.g., the pump 192 is rendered ineffective automatically or is turned off manually. In passing, it will be noted that the valve 178 opens at the same time as valve on the pressure within the cell 16 attaining a value of five p.s.i.g. Such opening of the valve 178 does not interfere with the sequential pressurization of the cells described above, but rather, on the contrary, aids in such sequential pressurizaticn in that the airflow through the partition 34 is facilitated by both the valves 176 and 178 being open. The preceding comments concerning the concurrent opening of the valves 180 and 178 also applies to pairs of valves associated with each of the cells 18-32, as will be obvious. It will be noted that the valves and 184 also open concurrently.

Now that all of the cells of the cell structure 10 are inflated to five p.s.i.g. and the pumps 192 and 194 are inactive or closed, it will be appreciated that rupture of or a leak in any of the cells 14-32 will result only in the escape of air from the affected cell accompanied by, at most, a reduction in pressure in the remaining cells to a value slightly less than five p.s.i.g. This is evident when it is considered that all the valves communicating with any particular cell are closed when the pressure within such cell falls below five p.s.i.g. and the pressure in the cell or cells immediately adjacent thereto falls below five p.s.1.g.

From the foregoing, it will be apparent that the valves 178, 182, 184 and 188 are not essential to the hereinbefore described order of sequentially inflating the cells of the cell structure 10. Accordingly, if it is only desired to sequentially inflate and deflate the cells in the abovedescribed order, the valves 178, 182, 184 and 188 can be dispensed with as well as the pump 194 and its connection to the cell 54. Dispensing with such elements will result on rupture or leakage from a cell only in a slight reduction in pressure of the cells disposed intermediate such cell and the pump 192.

Again assuming all the cells to be inflated to five p.s.i.g. and the pumps 192 and 194 to be closed initially, subsequent operation of the pump 192 to exhaust air from the cell structure 10 will result in the pressure within all of the cells being reduced to a sufficiently low value to close the valves 176-190, then the pressure with n cell 14 will be reduced to minus one p.s.i.g. at which time valve 176 opens to permit exhaustion of air from cell 16, followed by the sequential opening of valves 186 and 190 as the cells are successively exhausted. As was the case on inflating the cells, the pairs of valves 180 and 178, and 190 and 184 open concurrently to facilitate the passage of air through the partitions involved.

For reasons of symmetry, it is believed unnecessary to describe the procedure of successively inflating and deflating the cells in an order reverse to that hereinbefore described on closing the pump 192 and upon appropriate activation of the pump 194. It should be observed however that the arrangement disclosed in FIGURE 3 enables the cells to be sequentially inflated in one order and sequentially deflated in reverse order, if desired.

Although it is desired that both the partitions and the sidewalls of the cell structure 10 possess some flexibility, it is preferred that the inflation and deflation of the cells involve primarily a flexing of the sidewalls rather than the partitions. Attention is directed to FIGURES 5 and 6 for an appreciation of the structure of a portion of the partition 34 by way of example. The partition 34 is comprised of two layers 196 and 198 of flexible material impervious to air. The layers 196 and 198 can either or both be rubber or plastic, such as polyethylene for example, or a fabric impregnated with a flexible material to render it impervious. Almost any flexible material customarily used in inflatable structures is suitable for use as the layers 196 and 198. In the preferred construction there is interposed at spaced positions between the layers 196 and 198 is a plurality of parallel stiffening slats 200 which preferably extend normal to but terminate short of the sidewalls 202 and 204 connected by the partition 34. The adjacent surfaces of the layers 196 and 198 are secured to each other and the slats 200 disposed therebetween by a suitable adhesive or any other conventional means. The slats 200 can be of any material possessing a reasonable degree of stiffness. The slats 200 can be wood, such as oak, or preferably metal with aluminum being particularly well suited in view of the latters strength and Weight characteristics.

For a purpose hereinafter described, it is preferred that at least one side of the partition 34 is covered by a layer of porous material 206, which can be a layer of loosely woven material such as burlap.

An understanding of the character of the sidewalls of the cell structure will be appreciated upon reference to FIGURE 7 wherein a fragmentary sectional view of the sidewall 204 is comprised of a layer 208 of flexible material of a character such as hereinbefore indicated as suitable for layers 196 and 198 of the partition 34. In the preferred construction, the internal side of the layer 208 has a layer 210 of porous material suitably secured thereto as by an adhesive or the like. The porous layer 210 can becomprised of a layer of loosely woven fabric, such as burlap. The purpose of the porous layers 206 and 210 on the partitions and sidewalls, respectively, is to enable the passage of air through a cell even when such cell is collapsed tightly upon the cell being exhausted to a substantially subatmospheric pressure. Accordingly, the provision of the porous layers of material 206 and 210 can be considered as means for preventing the blocking of airflow through a cell.

Reference is now made to FIGURE 8, which is a schematic representation of a series of cells 212, 214, 216 and l 218 separated by partitions 220, 222 and 224. The cells 212-21 8 have flexible sidewalls 226, 228 and 230 that correspond in construction to the previously described sidewalls 202 and 204. The partitions 220-224 and end Walls 232 and 234 for the terminal cells 212 and 218 correspond in structure to the previously described exemplary partition 34.

A pump 236 similar to the pumps 192 and 194 is connected to the interior of the cell 212 through the end wall 232 by a flexible conduit 238, whereby ambient air can be selectively forced into the cell 212, or the latter exhausted to a subatmospheric pressure. Valves 240, 242 and 244 (corresponding in type to valve 109) are positioned in the partitions 220-224 and such valves (like valves 109 and 176-190) are connected to communicate with ambient air as a reference pressure.

Assuming the cells 212-218 to have initially been deflated to minus one pound per inch gauge or lower, and that the end wall 232 is fixed in position, all of the cells 212-218 are in collapsed condition (as cells 216 and 218 are shown in collapsed condition), the valves 240, 242 and 244 are all open and the end wall 234 is much closer to end wall 232 than shown. Operation of the pump 236 to force air into the cells 212-218 will initially increase the pressure in all the cells to minus one p.s.i.g. at which time all the valves 240-244 close with little if any expansion in size of the cells 212-218 having occurred. Entry of additional air will inflate and expand the cell 212 and move all of the cells 214-218 including the partition 220 to the left as a unit until the pressure in cell 212 reaches five p.s.i.g. whereupon the valve 242 opens and cell 214 commences to inflate and expand moving cells 216, 218 and the partition 222 to the left as a unit. FIGURE 8 shows the inflation process carried to this stage. The inflation process will obviously proceed to completion with the sequential inflation and expansion of the cells 214-218 with the end wall 234 being progressively moved further to the left as viewed in FIGURE 8.

With the inflation process of the structure shown in FIGURE 8 having been carried to completion, the pump 236 can be reversed in operation whereupon the pressure in all the cells 212-218 is reduced to five p.s.i.g. with the result that all the valves 240-244 are closed. Further deflation of the cell 212 results in the collapse of cell 212 due to ambient air pressure (particularly as the pressure in the cell approaches or becomes subatmospheric), and such collapse is accompanied by the cells 214-218 being moved as a unit to the right (as viewed in FIGURE 8) due to the action of ambient air pressure. Upon the air pressure in cell 212 dropping to minus one p.s.i.g., the valve 240 opens and deflation of cell 214 commences accompanied by collapse of the cell and movement of the cells 216 and 21-8 and partition 222 to the right as a unit due to the action of ambient air pressure. The process of sequential deflation of the cells 214-216 continues until all of the cells 212-218 are collapsed. The collapsing and expansion of the cells is primarily due to the flexibility of the sidewalls 226, 228 and 230, with the stiffening or internal bracing of the partitions 220-224 and the end walls 232 and 234 preferably being such that they undergo relatively little deformation in the process. Aside from the fact that the cells 212-218 expand and collapse in sequential order, the action is somewhat of the character of an accordion.

Though the structure shown in FIGURE 8 is shown horizontally disposed, it will be evident that the relative movement of partitions 220-224 and the end wall 234 with respect to the end wall 232 will remain basically the same without regard to the orientation of the end walls 232 and 234 (horizontal or vertical or whichever is uppermost), and without regard to which of the end walls 232 and 234 may be considered fixed in position. In other words, the inflation process can be considered as the operation of a motor that causes movement of cells still collapsed away from the cell to which the inflating pump is attached. On the other hand, the deflation process can be considered as the operation of a motor that causes movement of the still inflated cells toward the cell to which the exhausting pump is attached.

In view of the foregoing, it should now be apparent that the structure shown in FIGURES 1 and 2 is essentially self-erecting and self-collapsing. For example, as suming the structure to be in the erected condition shown in FIGURES 1 and 2 with the ground anchors for the cells 54 and 62 released as well as the anchor 108, operation of the pump 192 to exhaust air from the cell 14 to a sufliciently low pressure therein will cause or tend to cause clockwise movement of all the cells and the frame 12 as seen in FIGURE 1 until all the cells lie in collapsed condition on top of cell 14, and the elements of the frame 12 lie collapsed on top of the frame element 88.

The collapsing process will require little if any manual or other assistance, and yields the additional advantage of the structure being in a collapsed condition suitable for speedy re-erection or handling for removal. The limited flexibility afforded the partitions by the slats 200 enables the collapsed cell structure 10 to be rolled after detachment of the frame 12 and the ground anchors.

The erection process is essentially the reverse of the above-described collapsing process, with the cell structure 10 and the attached articulated frame 12 (if the latter is used) moving anticlockwise as seen in FIGURE 1 from the previously described collapsed condition thereof on operation of the pump 192 to pump air into cell 14. Little if any manual assistance is required in the erection process.

Though the principles of operation described in connection with FIGURES 3 and 8 are especially well suited to a cell shape and assembly such as the cell structure 10, it will be evident that the principles can have application to a wide-variety of serially connected cells, wherein the cells can have any desired shape or shapes and be assembled otherwise as desired. In short, according to the invention, cell structures presenting a wide variety of configurations on inflation and deflation can be made.

Should only the inflation features of the valve 109 be desired (other means for cell deflation being provided), the length of the valving element 120 can be such that the end of the latter never clears the openings 132, and alternatively, should only the deflation feature of the valve 109 be desired, the openings 134 can be omitted.

An alternative form of valve for use in lieu of valve 109 is shown in FIGURE 9 and designated generally at 246. The valve 246 is comprised of dished bonnet plates 248 and 250 suitably secured together and sealingly engaging the outer periphery of a flexible diaphragm 252 therebetween. The central portion of the bonnet plate 250 is formed as a tubular extension 254 that is preferably open ended, as shown. One end of a rod 256 of relatively small diameter is secured by conventional means 258 being engaged between coiled compression springs 260 and 261 seated against the bonnet plates 248 and 250, as shown. The other end of the rod 256 is secured to a valving element 262 having a sliding fit in the tubular extension 254. The valving element 262 can be solid when the free end of the extension 254 is open, otherwise the valving element 262 is preferably tubular.

The outer periphery of the bonnet plate 250 is sealingly secured by any suitable means about the periphery of an opening 264 in a flexible sidewall 266 of cells 268 and 270. The cells 268 and 270 are separated by a partition 272.

The bonnet plates 248 and 250 are provided with sets of perforations 274 and 276, whereby the opposite sides of the diaphragm 252 are in pressure communication with the pressure prevailing in the cell 268 and air pressure ambient to the cells 268 and 27 0.

The tubular extension is provided with aligned transverse openings 278, and has an integral nipple 280 about one of the openings 278 by means of which communication through such one opening 278 is established with the interior of the cell 270 through the partition 272 by means of flexible conduit means indicated at 282.

The operation of the valve 246 will be easily understood. For a predetermined range of pressure differentials between the pressure within the cell 268 and atmospheric pressure, the valving element 262 will close the openings 27 8; however, one end or the other of the valving element 262 will open the openings 278 upon the pressure differential having a greater or less value than the aforementioned predetermined pressure differential range. The predetermined range is determined by the geometry of the valve 246 and the strengths selected for the springs 260 and 261, as will be understood by those skilled in the art.

Opening and closing of the openings 278 controls the flow of air between the cells 268 and 270 in a manner analogous to that in which the valve 109 controls the flow of air between the cells 136 and 138 in FIGURE 4.

FIGURE 10 is a schematic illustration of the manner in which two sets of oppositely arranged valves 284 and 286, each valve being of the type shown in FIGURE 9, can be incorporated in a cell structure 288, provided with pumps 290 and 292 of the same type as pumps 192 and 194. If desired, the set of valves 286 and the pump 292 can be omitted. The structure and operation of the embodiment shown in FIGURE 10 is so analogous to the previously described structure and operation of the embodiments shown in FIGURES 3 and 8, that further description is believed unnecessary, it being understood that the end walls, partitions and sidewalls of the cell structure 288 possess the same basic characteristics hereinbefore set forth in connection with corresponding elements of the other described embodiments of the invention.

Other known types of valves that are functionally equivalent to the illustrated and described valves 109 and 246 can be employed in lieu thereof with the manner of such substitution being readily apparent to those skilled in the art in view of the illustration and described functions of the valves 109 and 246. Such other forms can reference the control of their valving elements to ambient or atmospheric pressure (as is preferred), or to any desired pressure standard, as by bellows, etc.

The pressures used in the description of the operation of the invention, namely, plus five and minus one p.s.i.g. were given only as exemplary values. The actual pressures selected for valve actuations should be based on the strengths of the containing structures with due consideration given to safety factors. The subatmospheric pressure selected for valve actuation will be such that destructive collapse and cell damage will not occur and yet be such as to facilitate collapse and retraction of the structure. Probably the pressures of plus five p.s.i.g. and minus one p.s.i.g. (particularly the former) are unsuited for the types and thicknesses of materials presently being employed in extant inflatable structures. For present day materials with ordinary thickness, at positive pressure ranging from slightly in excess of atmospheric to two or three p.s.i.g. is safe and adequate, with a negative pressure of from minus one to minus three p.s.i.g. being suitable.

If deemed expedient or desirable, the structure 10 can be used (especially when of a size suitable for sheltering one or two prone persons) without the frame 12 and without the provision of valve means in any of the partitions, with the passageway means in the partitions being retained so that all the cells can be inflated from a single position (unless separate means for inflating each cell is provided in which case the passageway means in the partitions can be omitted). Such simplified structure affords good insulation for persons or articles sheltered thereby. The partitions serve to reinforce and stabilize the structure when inflated, as well as limiting separation of the sidewalls (inner and outer walls of the structure considered as a whole), while not interfering excessively with compact storage and easy handling of the structure on deflation.

While preferred embodiments of the invention have been illustrated and described, the invention is such that numerous variations and departures can be made within the scope thereof. For example, the parts of the valves 109 and 246 indicated to be metallic by cross hatching can be non-metallic, such as being made of plastic. The doorway 68 can be omitted from the cell structure 10 as a shelter for antennas, radar equipment, or the like, the slats 200 and the frame 12 can be non-metallic (wood or plastic being suitable). If desired, the sidewalls 202 and 204 can be made of transparent and flexible plastic materials, with the porous layer 210 being omitted if necessary to preserve visibility through the cell structure 10, though such omission may entail some possibility of reducing the speed at which the structure can be collapsed.

Having set forth preferred embodiments of the invention in suflicient detail to give a full and complete understanding thereof, attention is directed to the appended claims in order to ascertain the actual scope of the invention.

I claim:

1. In an inflatable shelter comprising, a closed, doublewalled structure having a generally hemispherical configuration, a plurality of partitions in the double-walled structure subdividing the same into a series of lune-shaped cells, passageway means through each partition affording fluid communication between cells separated by such par- .13' titions, and pressure differential responsive means having communication with ambient atmospheric pressure for controlling fluid flow through such passageway means.

2. In an article of manufacture, the improvement comprising first and second inflatable cells separated by a partition, means defining a passageway affording fluid communication between the cells, valve means for closing the passageway, valve control means responsive to a fluid pressure differential in excess of a predetermined value for opening said valve means, said last means being in operative fluid pressure communication with the interior of the first cell and with a source of substantially constant fluid pressure, said valve means comprising a valving element mounted for reciprocable movement between first and second open positions through an intermediate closed position, said valve control means comprising a diaphragm operatively connected to the valving element, means affording fluid pressure communication between one side of the diaphragm and the interior of the first cell, and means affording fluid pressure communication between the other side of the diaphragm and the source of substantially constant pressure.

'3. A valve and control means therefor comprising, a bonnet having first and second sides, the central portion of the first side of the bonnet being constituted of a tubular extension having a closed outer end directed away from the second side of the bonnet, an open-ended tubular valving element slideable in the tubular extension, a diaphragm mounted in the bonnet between the first and second sides of the bonnet and secured to the inner end of the valving element, said diaphragm having an opening affording communication therethrough with the interior of the valving element, said tubular extension having a lateral opening therethrough, one of said sides of the bonnet having an opening therethrough, and means for affording fluid pressure communication between the side of the diaphragm adjacent the other side of the bonnet and a source of fluid pressure.

4. The combination of claim 3, wherein the valving element is provided with an opening intermediate its ends.

5. In an inflatable structure of the type including first and second cells separated by a partition having a valve controlled opening therethrough, an improved valve means for said opening comprising a bonnet secured to the partition and closing the opening in the latter, said bonnet having first and second sides facing respectively the first and second cells, the central portion of the first side of the bonnet being constituted of a tubular extension having a closed outer end directed away from the second side of the bonnet, an open-ended tubular valving element slideable in the tubular extension, a diaphragm mounted in the bonnet between the first and second sides of the bonnet and secured to the inner end of the valving element, said diaphragm having an opening affording communication therethrough with the interior of the valving element, said tubular extension having a lateral opening therethrough, one of said sides of the bonnet having an opening therethrough, and means for affording fluid pressure communication betwen the side of the diaphragm adjacent the other side of the bonnet and space ambient to the cells. 7

6. The combination of claim 5, wherein the valving element is provided with an opening intermediate its ends.

7. A valve and control means therefor comprising, a bonnet having first and second sides, the central portion of the first side of the bonnet being constituted of a tubular extension directed away from the second side of the bonnet, lateral passageway means in the tubular extension, a valving element slideable in the tubular extension for opening and closing the passageway means, a diaphragm mounted in the bonnet between the first and second sides of the bonnet, the central portion of the diaphragm being operatively connected to the valving element, and means for operatively affording fluid pressure communication between the opposite sides of the diaphragm and two sources of fluid pressure.

8. The combination of claim 7, wherein the effective length of the valving element is such that the valving element closes the passageway means only during an intermediate portion of its travel path.

9. In an inflatable structure of the type including first and second cells separated by a partition and having a side wall, the improvement comprising the side Wall of the first cell having an opening therethrough, a bonnet closing the opening having first and second sides facing the interior and exterior of the first cell respectively, the central portion of the first side of the bonnet being constituted of a tubular extension directed away from the secondside of the bonnet, lateral passageway means in the tubular extension and communicating with the interior of the second cell, a valving element slideable in the tubular extension for opening and closing the passageway means, a diaphragm mounted in the bonnet between the first and second sides of the bonnet, the central portion of the diaphragm being operatively connected to the valving element, and the first and second sides of the bonnet having openings therethrough for subjecting the opposite sides of the diaphragm to the pressures within the first cell and space ambient to the cells.

10. The combination of claim 9, wherein the effective length of the valving element is such that the valving element closes the passageway means only during an intermediate portion of its travel path.

11. 'In an inflatable structure of the type including a plurality of serially connected cells, the improvement comprising, in relation to each cell and the serially next cell respectively termed the preceding cell and the succeeding cell, means establishing fluid communication be tween the preceding and the succeeding cells, and means for closing fluid communication solely upon the pressure within the preceding cell being below a predetermined amount in excess of pressure ambient to the cells, said means including a pressure-differential responsive control device in operative fluid pressure communication with the interior of the preceding cell and space ambient to the cells.

12. The combination of claim 11, including a pump connected to the first of the serially connected cells.

13. In an inflatable structure of the type including a plurality of serially connected cells, the improvement comprising, in relation to each cell and the serially next cell respectively termed the preceding cell and the succeeding cell, means establishing fluid communication between the preceding cell and the succeeding cell, means for closing said fluid communication solely upon the pressure differential between the interior of the preceding cell and space ambient to the cells lying within a predetermined range, said closing means including a pressuredifierential responsive control device in operative fluid pressure communication with the interior of the preceding cell and space ambient to the cells.

1 4. The combination of claim 13, wherein the preceding and successive cells are separated by a partition, and means for imparting stiffness to the partition in at least one direction.

15. The combination of claim 13, including a pump connected to the first of the serially connected cells.

16. In an inflatable structure of the type including a plurality of serially connected cells, the improvement comprising, in relation to each cell and the serially next cell respectively termed the preceding cell and the succeeding cell, means establishing fluid communication between the preceding cell and the succeeding cell, means for closing said fluid communication solely upon the pressure differential between the interior of the preceding cell and space ambient to the cells lying within a predetermined range, said closing means including a pressure differential responsive control device in operative fluid pressure communication with the interior of the preceding cell and space ambient to the cells, and means in each cell for preventing blockage of fluid flow on collapse of such cell.

References Cited UNITED STATES PATENTS Leatherman 135-1 Windsor et al 13763 16 Richardson et al. 135-1 Leatherman et a1. 135-1 Fischer 135-1 Snyder 137-493 Swallor 135-1 REINALDO P. MACHADO, Primary Examiner.

HARRISON R. MOSELEY, Examiner.

10 T. BLUMENSTOCK, L. J. SANTISI,

Assistant Examiners. 

1. IN AN INFLATABLE SHELTER COMPRISING, A CLOSED, DOUBLEWALLED STRUCTURE HAVING A GENERALLY HEMISPHERICAL CONFIGURATION, A PLURALITY OF PARTITONS IN THE DOUBLE-WALLED STRUCTURE SUBDIVIDING THE SAME INTO A SERIES OF LUNE-SHAPED CELLS, PASSAGEWAY MEANS THROUGH EACH PARTITION AFFORDING FLUID COMMUNICATION BETWEEN CELLS SEPARATED BY SUCH PARTITIONS, AND PRESSURE DIFFERENTIAL RESPONSIVE MEANS HAVING COMMUNICATION WITH AMBIENT ATMOSPHERIC PRESSURE FOR CONTROLLING FLUID FLOW THROUGH SUCH PASSAGEWAY MEANS. 